help2man: upgrade 1.48.4 -> 1.48.5

   * Use @samp{} around the option in the menu description for "--help
     recommendations" to avoid rendering the -- as endash.
   * Update French translations
   * Update standards version to 4.6.0 (no changes).

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>